Automatic electric fire-alarm.



J. W. WAHL. AUTOMATIC ELECTRIC FIRE ALARM. APPLICATION FILED MAR. I3. 1915. 1,284,950. Patented Nov. 12,1918.

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UNITED STATES PATENT OFFICE.

JACOB W. WAI-IL, OF NEW YORK, N. Y., AS SIGNOR TO S. M. LOOMIS, OF CINCINNATI,

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AUTOMATIC ELECTRIC FIRE-ALARM.

Application filed March 13, 1915.

To all whom it may concern Be it known that I, JACOB W. WVAHL, a subject of the German Empire, and a resident of New York, in the county of Kings and State of New York, have invented a new and useful Automatic Electric Fire-Alarm,

. of whichthe following is a specification.

This invention relates to alarms, and particularly to fire alarms, having for its primary object to provide a simple and efiicient means for automatically actuating a signal when the heat within a room, house or building has reached a degree sufficient to actuate the alarm device.

A further object of the invention is to provide a thermostatic arrangement which is composed of but few Simple and readily assembled parts, which is so assembled as to prevent breakage, wear or derangement, which, when once installed requires no further attention, and which will provethoroughly eflicient in sounding an alarm when a predetermined temperature in a room has been reached.

With these objects in View, together with others, which will appear as the description proceeds, the invention resides in the novel formation, combination and arrangement of parts, all as will be described more fully hereinafter, illustrated in the drawings, and particularly pointed out in the claims.

The invention will be best understood by reference to the accompanying drawings, wherein Figure 1 is a sectional view taken through a signal sounding device constructed in accordance with the invention;

Fig. 2 is a bottom plan view of the device shown in Fig. 1;

Fig. 3 is a side elevation illustrating the alarm sounding means as applied to a conventional form of electric bell;

Fig. at is a top plan view of the device shown in Fig. 3; and

Fig. 5 is a diagrammatic view illustrating the manner in which the thermostatic device may be wired to actuate an alarm remote from the place of installation of the thermostat.

Referring now more particularly to the drawings, A represents a thin metallic shell or bulb, the same being formed at one side to provide an annular neck portion capable of seating securely within a seat, socket or base B. The shell or bulb A as well as the socket Specification of Letters Patent.

Patented Nov. 12, 1918.

Serial No. 14,055.

B, may be formed of copper or other metal constituting an eflicient conductor. The bottom of the socket portion B is spaced from that of the bulb A, and secured to the bulb bottom and projecting to the interior thereof,

are spaced binding posts C and D which constitute the terminals of an electric circuit.

The post C is insulated from the base or socket B and is threaded through the plate or block H, while the post D is electrically connected with the said socket. The inner extremity of the post C normally extends into close proximity to the bottom of the bulb A as illustrated in Fig. 1 of the drawing, and is capable of being adjusted toward or away from the same.

Secured to the base or bottom portion of the shell A is a thin sheet or diaphragm F of copper or other material capable of readily expanding when subjected to heat. An opening G is arranged within the shell A over the thin sheet to enable the heat within the shell to act directly upon the underlying flexible sheet F to readily expand the same.

Arranged centrally of the base or socket B is a set screw E, the latter being capable of being moved toward and away from the diaphragm F, whereby the degree of eX- pansion of the latter may be regulated. The screw E is insulated from the socket as shown.

In practice, the thermostat above described may be associated with a bell in a manner indicated in Figs. 3 and 4 of the drawing, or may have its posts C and D connected with a bell at a remote point, as is illustrated in Fig. 5. When the heat within a room reaches a degree sufficient to create expansion of the diaphragm F until the latter engages with the post C, the electric circuit which includes the alarm will be closed through the post C, diaphragm F, base 13 and post D, whereupon the alarm is sounded. To adjust the thermostat so as to enable the same to operate at the desired temperature, the screw E may be regulated, the latter controlling the degree of outward movement which the diaphragm G will assume.

WVhile the above is a description of the preferred embodiment of the invention, it is obvious that various changes in the minor details of construction and arrangement of parts may be resorted to, without departing from the spirit of the invention or exceeding the scope of the claims.

What is claimed is 1. In a device of the class described, a socket, a shell arranged within said socket and capable of expanding when subjected to heat, the said shell and socket being electrically connected, contacts in said socket, one of said contacts being insulated from said socket, said contacts being included in an electric switch circuit, and an adjusting screw in said socket for limiting the degree of expansive movement of said shell, substantially as described.

2-. In a device of the class described, a socket, a pair of contacts projecting inwardly from the bottom of said socket and being spaced from each other, one only of said contacts being insulated from said socket, the said contact being capable of being adjusted in said socket, an adjusting screw threaded through said socket between said pair of contacts, a bulb adapted to seat in said socket, a thin diaphragm stretched across the base of said bulb and being electrically connected with said socket, the said diaphragm being adapted to engage said adjustable contact, and the said contacts constituting the terminals of an electric circuit.

3. In a device of the class described, the combination with a metallic socket of a bulb adapted to seat in said socket, a thin metallic diaphragm on the base of said bulb adapted when heated to move toward the bottom of said socket, the said diaphragm being engaged at its edges with said socket, a contact threaded through the bottom of said socket and insulated from the latter and being adapted to be engaged by the said diaphragm when the latter is extended, a second contact in said socket and electrically connected therewith, the said contacts constituting the terminals of an alarm circuit, and an adjusting screw insulated from and threaded through said socket and being adapted to limit the expansive movement of said diaphragm.

JACOB W. WAHL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

